In general, a motor includes a stator and a rotor. When AC voltage is applied to a coil wound on the stator, the rotor rotates by a rotational magnetic field, and the rotation of the rotor causes a rotation of a load applied to a rotor shaft. For instance, in the case of drum washing machines, a drum is connected to the rotor shaft to thereby rotate with the rotor.
As described above, in order to supply electricity to the motor or to apply an electric current to the motor, the stator assembly of the motor includes a connector connected with a coil wound on the stator. Korean Patent No. 10-1013781 discloses a stator assembly, and FIG. 1 is an exploded perspective view of the stator assembly.
As shown in FIG. 1, the stator assembly according to the prior art includes a stator core 100, and upper and lower insulators 210 and 220 respectively covering upper and lower portions of the stator core 100. The stator core 100 includes a circular base part 110, which is a central part of the stator core 100, and teeth 120 radially formed on an outer face of the base part. Each of the teeth 120 includes a tooth end portion 125 formed at the end portion opposed to the base part and has a T-shaped cross section. A coil is wound on each of the teeth 120 in a state where the upper and lower insulators 210 and 220 are joined together.
At an upper portion inside the upper insulator, the upper insulator 210 includes a tap terminal 211 for a power terminal, which is a connector for connecting a power line, and another tap terminal 212 for connecting a common terminal (neutral point) of each phase. A sensor cover 215 includes a hall sensor (not shown) mounted therein, and a tap connection part 216 connected to the tap terminal 211 for the power terminal and a power terminal part 217 for connecting electricity are formed in an outward direction opposed to the tap connection part 216. The tap connection part 216 and the power terminal part 217 are connected by a lead wire (not shown) disposed inside the sensor cover.
According to such a structure of the stator assembly of the prior art, the upper insulator 210 and the lower insulator 220 are made from resin molding, and hence, a great deal of resin moldings are used, and a size of the sensor cover 215 is increased because the tap terminal 211 for the power terminal and the tap terminal 212 for the common terminal are formed inside the upper portion of the upper insulator 210, namely, formed more inside than the base part 110.
Accordingly, in order to solve the above problems, the inventors of the present invention introduce a new structure to join the sensor cover in a state where the surface of the stator core is insulated by powder coating without the structure that the entire of the stator core is insulated by the insulator, so as to reduce an amount of resin molding, simplify the manufacturing process and reduce manufacturing costs.